How do I flash the 930V software to my phone

I bought this S7 and was told that it was originally a 930v but had been flashed to 930U ROM. I thought nothing of it but I went to turn of WIFI Calling and realized that it's not an option with the 930U. It's fairly important option for me. can I flash my rom back to 930V and if so where do I find a ROM. or is there another way?